King David expresses his absolute devotion to finding a resting place for the Ark of the Covenant through a solemn oath and conditional vow [אבן עזרא, מלבי״ם, מצודת דוד]. He is completely prepared to sacrifice all personal and royal conveniences for this cause. The primary approach among commentators is that he is not making a literal promise to completely avoid entering his own home. Instead, he uses exaggerated language to emphasize a deep emotional truth. Sitting in his house will bring him absolutely no pleasure or peace as long as he has not found a permanent place for God [רד״ק, ביאור שטיינזלץ]. This profound sense of unrest echoes his earlier conversation with Nathan the prophet, where David expressed his discomfort at living in a house of cedar while the Ark of God remained in a temporary tent [רד״ק].
The oath specifically targets two centers of royal luxury. The first is his personal dwelling space. This is not merely a standard building, but a space specially prepared for the king to sit in [מצודת דוד]. While [אבן עזרא] identifies this simply as David's house in Jerusalem, [אלשיך] views it as a magnificent, private royal canopy set up within the palace.
The second focus of his oath is his bed. This refers to a piece of furniture designed specifically for comfort and pleasure [מלבי״ם, מצודת ציון], beautifully arranged with fine linens exactly as is fitting for a monarch [רד״ק, אלשיך, מצודת דוד, מצודת ציון]. David swears that he will not use this luxurious bed for a full night of regular sleep or personal enjoyment. Instead, he commits to only taking temporary sleep outside of his royal comforts until his central mission is complete [אלשיך].